We experimentally investigate the removal of several microns thick plasma-enhanced chemical vapour deposition SiO 2 films by a localized dynamic fracture due to confined laser–matter interaction with the silicon substrate (punching) using 10 ps laser pulses at 355 nm. A near order of magnitude increase in the punching threshold fluence (from ∼0.1 to ∼1 J cm −2 ) is observed as the ratio between the spot size and the film thickness is scaled down, in order to produce high aspect ratio openings in the film. An opening radius of about twice the film thickness appears to be an approximate practical limit. A high aspect ratio opening is created by a cone fracture of the film and the ejection of a conoid film segment (flyer). We discuss mechanisms of brittle fracture that may lead to the observed patterns.

中文翻译：

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PECVD SiO 2薄膜激光冲孔的结垢效应和脆性断裂机理

我们实验性地研究了由于局限性动态断裂而导致的几微米厚的等离子增强化学气相沉积SiO 2膜的去除，这是由于在355 nm下使用10 ps激光脉冲与硅衬底之间的局限性激光-物质相互作用（打孔）。随着光斑尺寸和膜厚的比例缩小，在孔中产生高纵横比的开口，观察到打孔阈值通量几乎增加了一个数量级（从0.1到1 J cm -2）。电影。大约两倍于膜厚度的开口半径似乎是一个实际的极限。高纵横比的开口是通过薄膜的圆锥形断裂和圆锥形薄膜片段（飞片）的弹出而产生的。我们讨论了可能导致观察到的模式的脆性断裂机制。